Sheet end stabilizer and method of use



Jan. 17, 1967 c. P. CRAMPTON 3,

SHEET END STABILIZER AND METHOD OF USE Filed April '7, 1965 2Sheets-$heet l INVENTOR. CHARLES P. CRAMPTON 'y w% I ATTORNEY Jan. 17,1967 c. P. CRAMPTON SHEET END STABILIZER AND METHOD OF USE 2Sheets-Sheet 2 Filed April '7, 1965 INVENTOR. CHARLES P. CRAMPTON 2 ATORN i) United States Patent Ofifice 3,298,684 Patented Jan. 17, 19673,298,684 SHEET END STABILIZER AND METHOD OF USE Charles P. Crampton,Hamilton, Ohio, assignor to The Hamilton Tool Company, Hamilton, Ohio,at corporation of Ohio Filed Apr. 7, 1965, Ser. No. 446,302 20 Claims.(Cl. 27169) This invention relates to improvements in a collator andpress delivery, and concerns the arranging of sheets severed from acontinuously moving web of material such as paper, in single or multipleply form.

An object of the invention is to provide improved means for severingsheets from a continuously moving web, and compiling the severed sheetsin echelon arrangement with great precision and rapidity, to maintainreliable scheduled production unattended by frequent malfunctioning ofthe machinery.

Another object of the invention is to attain maximal reliability andefliciency in the delivery of sheets as stated, utilizing simple andinexpensive means which easily may be applied to machines in use, aswell as to machines in the process of manufacture.

A further object is to provide means for the purposes stated, whichdemands practically no maintenance attention, and is characterized byextraordinary durability and longevity.

The foregoing and other objects are attained by the means describedherein, and as disclosed in the accompanying drawings, in which:

FIG. .1 is a fragmentary top plan view of a delivery in which isembodied the means of the present invention.

FIG. 2 is a cross-sectional view taken on line 22 of FIG. 1.

FIG. 3 is a perspective view of a sheet guide which constitutes anelement of the invention.

With reference to the accompanying drawings, the reference character Windicates a flexible web of paper or the like, which may be fedcontinuously from a source of supply such as a rotary reel, not shown.The web moves at high linear speed between a cut-off roll 6 and an anvilroll 8, which cooperate to transversely sever the advancing web atprescribed locations, to produce a continuous flow of sheets S1, S2 andS3. The severed sheets are to be deposited upon a rapidly movingconveyor 10, with the sheets overlapping one another in succession toproduce an echelon arrangement. The overlapped sheets advance to theleft in FIG. 2, and are eventually batched and deposited in or upon asuitable receiver, not shown.

The cut-off roll may carry one or more knives or cutters 12 to sever theweb and thereby produce sheets of a predetermined length. Rolls 6 and 8are power driven in opposite directions of rotation.

From the cut-off station, the severed sheets pass over a bridgingelement or plate 14 which directs the sheets in succession to the bitebetween gripper roll 16 and gripper wheel (MW wide) 18. The gripper rolland wheel are rotated in opposite directions at a surface speedexceeding the speed of web W, so as to tension sheet S1 and therebyensure separation of said sheet from the web as cutter 12 penetrates theweb. The greater speed imparted to sheet S1 serves also to propel thesheet over the top of sheet S2 with a partial overlap, to produce anechelon arrange ment of the sheets.

From the disclosure at the left in FIG. 2, it is apparent that theleading edge 20 of sheet S2 overlaps the trailing edge 22 of sheet S3;in like manner, projection of sheet S1 by the gripper roll and wheelwill cause the leading edge 24 of S1 to over-ride the trailing edge 26of sheet S2, by an amount approximating the overlap of sheet S2 uponsheet S. As will be understood, the upper run of conveyor 10 is drivenat a slower linear speed than the surface speed of gripper roll 16 andgripper wheel 18. The speed of the conveyor may be subject toregulation, so as to establish the amount of sheet overlap desired uponthe conveyor.

The pair of rolls 6-8, and gripper roll 16 and gripper wheel 18, as wellas the conveyor roll 28, may be driven by conventional means common inthe art. Power driven also is the shaft 30 carrying the knock-downfingers 32, which perform to flatten down the trailing ends ofsuccessive sheets upon a stationary bridging element 34 just prior toprojection of a succeeding sheet by the gripper roll. The bridgingelement 34 is mounted upon the machine frame 9, and spans the spacebetween the lower gripper roll 16 and the support roll 28 of conveyor10.

The knock-down device may be constituted of a series of spaced wires orlight-weight thin bars, having ends 36 fixedly secured in spacedrelation upon a mandrel 38 which rotates in clockwise direction withshaft 30. When shaft 30 is rotated to displace the finger 32 from thepath of advancement of a sheet such as S1, said sheet may freely beprojected by the gripper roll to overlie a portion of the precedingsheet, for example sheet S2. The timing of knock-down shaft 30 is suchthat fingers 32 will never be in a position to interfere with forwardadvancement of a sheet projected by tthe gripper roll.

In the past, operation of the delivery sometimes was interrupted byreason of failure of a gripper-projected sheet to properly over-ride apreceding sheet in sufficiently flattened condition; that is, theleading end of the projected sheet sometimes had a tendency to followthe periphery of gripper roll 16, and in so doing, tended to under-riderather than over-ride, the trailing end 26 of a preceding sheet. Thisresulted in a jam at the knockdown mechanism, necessitating a halt inoperation until the jam of sheets could be cleared.

One of the objects of the present invention is to obviate theabove-mentioned difficulty and thereby avoid resultant expensive delaysand annoyances.

It will be noted that the lower gripper roll 16 is provided along itslength with a multiplicity of narrow radial grooves 40 spaced apart, thegrooves being of substantial depth, and each groove having a base 42defined by parallel side walls 44. The depth of each groove greatlyexceeds the width thereof preferably, and all the grooves are of uniformdepth.

The bases of the grooves provide tracks upon which may rest a series ofsheet stabilizers 46 (see FIG. 3), which fit loosely between the sidewalls of the grooves so that the stabilizers may remain stationary whilethe roll 16 rapidly rotates. The side walls of the grooves support thestabilizers in upright position, or in planes normal to the axis ofrotation of the roll.

The stabilizers 46 are identical one to another, and FIG. 3 disclosesone such stabilizer in detail. It comprises a piece of sheet material ofuniform thickness, shaped to provide a head 48 and an elongate integraltail 50. The upper and lower edges 52 and 54 defining the tail 50, maybe straight edges convergent in the direction of the free end of thetail. The head 48 likewise may be defined by upper and lower straightedges 56 and 58, respectively, which are divergent in the direction ofthe outer end 60 of the head. The lower edges 54 and 58 meet at anobtuse angled juncture 62, which is free of contact with the base 42 ofa groove when the stabilizer is seated therein.

As FIG. 2 clearly indicates, the lower straight edges of the head andthe tail have point-contact with the track provided by the groove base,so that running friction between the stabilizer and the track is held toa practical minimum. To further minimize running friction, thestabilizer may be formed of Teflon, Delrin, or a similar plasticsubstance which possesses self-lubricating, wear-resistentcharacteristics. In the example illustrated, the thickness of thestabilizer approximates one-sixteenth, which allows gripper wheel 18 1inch wide) to be placed directly over sheet stabilizer 46 if desired.

In order that the upper gripper wheel 18 may cooperate with the lowergripper roll in propelling or projecting a sheet such as S1 withoutinterference by the stabilizer, the height dimension of the stabilizertail may be less than the depth of groove 49, where the roll and wheelestablish full contact with the sheet. The line of full contact, ofcourse, is in a plane which includes the axis of roll 16.

At the head end of the stabilizer, the upper sheet-support edge 5-5projects toward a knock-down finger 32, and is substantially tangent tothe outer periphery of roll 16. Edge 56 generally will be disposed in aplane which is above, and substantially parallel to, the upper reach ofconveyor lit It is desirable that the stabilizer head, and particularlythe delivery end of its edge 56, be located over a portion of thebridging element 34, so that the leading end 24 of a sheet such as S1may be firmly supported against downward sag until said leading endovertakes the trailing end of a preceding sheet, S2, traveling in thesame direction. Thus, the leading end 24 of a sheet being projected bygripper roll 16 and gripper wheel 18, is precluded from underlapping thetrailing end of the preceding sheet.

To ensure the stabilizer against displacement as the lower gripper roll16 rotates, the head end of the stabilizer may be provided with a notch64 to engage the forward edge 65 of bridging element or plate 34. Ifdesired, the free end of the stabilizer tail 5i may for the same purposebe tucked beneath the free edge portion 63 of bridging element 14, asshown in FIG. 2. Either or both of these expedients may be employed topreclude rotation of the stabilizer with the lower gripper roll.

It should be understood that all of the sheet-supporting devices orstabilizers 46, will bear the above disclosed relationship to thegripper roll and wheel and to those elements of the machine which actupon sheets projected by the gripper roll and wheel in the direction ofadvancement of conveyor 10. The web W and the sheets severed therefrom,may be single-ply, multiple-ply, or laminate in character. In manyinstances the web may comprise several layers of paper between which maybe interposed copy-paper layers carbonized or otherwise treated for theproduction of copies. Portions severed from such webs are collated bythe machine in the same manner, and With the same effectiveness, assingle sheets.

It is to be understood that various modifications and changes may bemade in the structural details of the device, within the scope of theappended claims, without departing from the spirit of the invention.

What is claimed is:

1. Apparatus for stacking upon a receiving surface a series of flexiblesheets fed in linear succession from a source of supply, said apparatuscomprising: driven means including the periphery of a rotary gripperroll for projecting said sheets in succession, with corresponding endsof successive sheets in leading position; a rotary knockdown deviceadjacent to the driven means aforesaid, to engage only the trailing endportions of the sheets projected by said driven means and flatten saidend portions upon the receiving surface; and a sheet end stabilizerintermediate the driven means and the knock-down device, for guiding theleading ends of successive projected sheets tangentially from thegripper roll periphery.

2. Apparatus according to claim 1, wherein the receiving surfacecomprises a moving conveyor traveling at a lesser surface speed thanthat of the gripper roll periphery, and wherein the stabilizer guidesthe leading ends of the sheets onto the conveyor in a plane which isabove and in substantial parallelism with the plane of the conveyor.

3. Apparatus for stacking upon a receiving surface a series of flexiblesheets fed in linear succession from a source of supply, said apparatuscomprising: driven means including a rotary gripper roll having aperiphery for projecting said sheets in succession, with correspondingends of successive sheets in leading position, said grip per roll havingformed in its periphery a plurality of narrow radial grooves spacedapart, the grooves each having a base defined by parallel side walls, asheet stabilizer upon and supported by the roll and loosely fitted ineach groove between the side walls thereof, said stabilizers each havinga head end and a tail adapted to be supported upon the base of a groove,an upper guide edge on each stabilizer extended substantiallytangentially from the supporting gripper roll periphery toward the sheetreceiving surface, for precluding the leading ends of the sheets fromfollowing the moving periphery of the gripper roll, and directing saidends toward the receiving surface in substantial parallelism with thelatter; and means precluding rotation of the stabilizer with the gripperroll.

4. Apparatus according to claim 3, wherein the receiving surfacecomprises a moving conveyor traveling at a lesser surface speed thanthat of the gripper roll periphery, and wherein the stabilizer edgeguides the leading ends of the sheets onto the conveyor in a plane whichis spaced above the plane of the conveyor.

5. Apparatus for stacking upon a receiving surface a series of flexiblesheets fed in linear succession from a source of supply, said apparatuscomprising: driven means including a rotary gripper roll underlying thesheets and raving a periphery for engaging and projecting said sheets insuccession, with corresponding ends of successive sheets in leadingposition, said gripper roll having formed in its periphery a pluralityof narrow radial grooves spaced apart, the grooves each having a basedefined by a pair of spaced side walls, a stationary sheet stabilizercomprising a flat head loosely fitted in each groove between the sidewalls thereof and supported upon said base of the groove, an upper guideedge on each stabilizer head, with said guide edge extendedsubstantially tangentially from the gripper roll periphery toward thesheet receiving surface, to preclude the leading ends of the projectedsheets from following the moving periphery of the gripper roll.

6. Apparatus according to claim 5, wherein the receiving surfacecomprises a planar moving conveyor traveling at a lesser surface speedthan that of the gripper roll periphery, and wherein the stabilizerguide edge directs the leading ends of the projected sheets onto theconveyor in a plane which is spaced above, and in substantialparallelism with, the plane of the conveyor.

7. Apparatus according to claim 6, wherein is included a knock-downdevice located between the stabilizer head and the conveyor, operativeto depress the trailing end of a projected sheet in advance ofprojection of a succeeding sheet over the conveyor by action of thegripper roll.

8. Apparatus for stacking upon a receiving surface a series of flexiblesheets fed in linear succession from a source of supply, said apparatuscomprising: driven means including a rotary gripper roll having aperiphery for engaging the undersides of and projecting said sheets insuccession, with corresponding ends of successive sheets in leadingposition, and a stationary sheet stabilizer slidingly mounted upon andsupported by the gripper roll, and said stabilizer including means topreclude the leading ends of the roll-projected sheets from followingthe contour of the gripper roll periphery as said roll rotates.

9. Apparatus according to claim 8, wherein the means last mentionedincludes a sheet-guiding surface directing the leading ends of theprojected sheets in substantial parallelism with the plane of thereceiving surface, said sheet-guiding surface being substantiallytangential to the periphery of the gripper roll.

10. Apparatus according to claim 9, wherein the receiving surfacecomprises a planar moving conveyor traveling at a lesser surface speedthan that of the gripper roll periphery, to induce stacking of thesheets in echelon fashion upon the conveyor.

11. Apparatus for stacking upon a receiving surface a series of flexiblesheets fed in linear succession from a source of supply, said apparatuscomprising: driven means including a rotary gripper roll having aradially grooved periphery to contact and project said sheets insuccession, with corresponding ends of successive sheets in leadingposition, the radial grooves of the gripper roll being spaced apartalong the length of the roll, and each groove having a base defined by apair of spaced side walls, a flat elongate sheet-stabilizer looselyfitted between the side walls of each groove, each stabilizer comprisinga head and an integral tail supported within a groove, a straightbearing edge on the head, and a straight bearing edge on the tail, saidbearing edges meeting at an obtuse angle intermediate the ends of thestabilizer, said edges being adapted to ride in point-contact abutmentupon the base of a roll groove as the roll rotates relative to thestabilizer, a guide edge on the head disposed outside the limits of thegroove, said guide edge being substantially tangential to the peripheryof the gripper roll, and the stabilizer tail at the point of contact ofthe bearing edge of the tail upon the groove base, being of lesserheight than the depth of the groove.

12. Apparatus according to claim 11, wherein at least one end of thestabilizer includes an abutment to contact a stationary part of theapparatus, for precluding rotation of the stabilizer with the gripperroll.

13. Apparatus according to claim 11, wherein the stabilizer is formed ofa self-lubricating, Wear-resistant resin material selected from thegroup consisting of acetyl and polytetrafluoroethylene resins.

14. A sheet-stabilizer for application to a gripper roll having a radialgroove defined by a groove base and a pair of spaced side wallsextending outwardly from said base to the periphery of the roll, saidstabilizer comprising: a flat elongate body loosely receivable betweenthe side walls of the groove, with point-contact abutment upon the baseof the groove, and a sheet-guiding edge on the body disposed outside thelimits of the groove, said guiding edge being substantially tangentialto the periphery of the gripper roll, and an abutment on the stabilizerbody for anchoring the body against rotation with the gripper roll.

15. A sheet-stabilizer according to claim 14, wherein the abutmentaforesaid is exposed outside the limits of the groove of the gripperroll.

16. A sheet-stabilizer according to claim 14, wherein the stabilizerbody is formed of a self-lubricating, wearresistant resin materialselected from the group consisting of acetyl and polytetrafiuoroethyleneresins.

17. Apparatus according to claim 1, wherein said sheets are projectedfreely in advance of being contacted by said knock-down device.

18. Apparatus for stacking upon a receiving surface a series of flexiblesheets fed in linear succession from a source of supply, said apparatuscomprising: means forming a receiving surface, driven means closelyadjacent to said receiving surface including the periphery of a rotarygripper Wheel for projecting said sheets in succession onto said surfacewith corresponding ends of successive sheets in leading position, thesheets being engaged on the under surface thereof by said roll, a rotaryknockdown device between and closely adjacent to said driven means andsaid surface operative to engage only the trailing end portions of thesheets projected by the driven means and flatten said end portions onsaid receiving surface, sheet stabilizing means lying between the drivenmeans and said knock-down device for supporting successive sheetsprojected tangentially from the gripper roll periphery onto saidsurface, said stabilizing means embodying a plurality of elongatemembers extending transversely across the gripper roll and having topedges on and along which said successive sheets move, means maintainingsaid elongate members in stationary operative position relative to thegripper roll, said sheet receiving surface comprising an end portion ofthe top run of an endless conveyor moving in the same direction as theprojected sheets, and said knock-down device comprising a rotary shaftover and extending across said end portion of said conveyor top run anda plurality of flexible fingers carried by said rotary shaft and turnedthereby in a rotary path to move in the direction of movement of theprojected sheets when knocking the sheets down toward the said receivingsurface.

19. Apparatus according to claim 18, with a bridging member between saidgripper roll and the said end portion of the said top run of saidendless conveyor, said bridging member having a top surface lying belowthe said top edges of said elongate members and substantially in theplane of said sheet receiving surface.

26. Apparatus for stacking upon a receiving surface a series of flexiblesheets fed in linear succession from a source of supply, said apparatuscomprising: a cut-off roll and a cooperating anvil roll between which asheet of flexible material passes to be cut transversely to produce aflow of individual sheets moving in one direction, means forming areceiving surface comprising an end portion of the top run of an endlessconveyor moving in said one direction of flow of said sheets, drivenmeans closely adjacent to said end portion of said conveyor including agripper wheel and an underlying gripper roll between which wheel androll said sheets are fed and from which they are projected by saidgripper roll in succession onto said receiving surface withcorresponding ends of successive sheets in leading position, saidgripper roll having a radially grooved periphery in contact with theperiphery of said gripper wheel, the radial grooves of the gripper rolleach having a base defined by a pair of spaced side Walls, fiat elongatesheet-stabilizers each loosely fitted in one of said groovestransversely of and between said wheel and roll, each stabilizercomprising a head and an integral tail, said head and tail having bottombearing edges intermediate the ends of the stabilizer, said bearingedges resting and riding upon the base of a groove as the roll rotatesrelative to the stabilizer, a top guide edge on the head of eachstabilizer outside the limits of the groove, said top guide edge beingsubstantially tangential to the periphery of the gripper roll, thestabilizer tail at the point of contact of the bearing edge thereof uponthe groove base being of lesser height than the depth of the groove, abridging element extending from adjacent the periphery of the anvil rollto and terminating over a terminal portion of said tail of eachstabilizer, a bridging element between said gripper roll and said endportion of said endless conveyor, the last mentioned bridging elementhaving a top surface lying below the said top guide edges of thestabilizers and substantially in the plane of said sheet receivingsurface, coupling means between said head of each stabilizer and saidlast mentioned bridging member, and a rotatable knock-down meansoverlying said end portion of said endless conveyor operative to engagethe trailing end portions of the sheets projected by said driven meansand flatten said end portions on said receiving surface.

References Cited by the Examiner UNITED STATES PATENTS 5/1944 Miller.12/1958 Richards 271-69

1. APPARATUS FOR STACKING UPON A RECEIVING SURFACE A SERIES OF FLEXIBLESHEETS FED IN LINEAR SUCCESSION FROM A SOURCE OF SUPPLY, SAID APPARATUSCOMPRISING: DRIVEN MEANS INCLUDING THE PERIPHERY OF A ROTARY GRIPPERROLL FOR PROJECTING SAID SHEETS IN SUCCESSION, WITH CORRESPONDING ENDSOF SUCCESSIVE SHEETS IN LEADING POSITION; A ROTARY KNOCKDOWN DEVICEADJACENT TO THE DRIVEN MEANS AFORESAID, TO ENGAGE ONLY THE TRAILING ENDPORTIONS OF THE SHEETS PROJECTED BY SAID DRIVEN MEANS AND FLATTEN SAIDEND PORTIONS UPON THE RECEIVING SURFACE; AND A SHEET END STABILIZERINTERMEDIATE THE DRIVEN MEANS AND THE KNOCK-DOWN DEVICE, FOR GUIDING THELEADING ENDS OF SUCCESSIVE PROJECTED SHEETS TANGENTIALLY FROM THEGRIPPER ROLL PERIPHERY.